The present invention relates to a stapler apparatus which binds media to be bound (a sheet bundle), such as a plurality of documents printed with a copying machine, a printer, or a composite of machines thereof, etc., with staples.
Conventional stapler apparatuses of this type comprise a built-in direct current motor, the drive of the direct current to recover to within an idle position region which is the initial position after the binding process by the binding means, are equipped with a nipping means to hold the binding media, a forming means to form staples into U-shapes, a driving means to drive U-shaped staples into the binding media being nipped and a binding means comprising a bending means to bend the leading ends of staples driven into the binding media and are disposed with an idle position sensor that can detect that the binding means has stopped within the idle position region. Using the output from this idle position sensor, it grasps the position where the binding means has entered within the idle position region and stops the supply of electric power to the direct current motor. At the same time, an electric brake is applied by electrically shorting the input terminal, or by applying a reverse drive to stop the direct current motor, the rotation thereof continues under inertia. Note that the idle position region is set to a regional width wherein the binding means can surely stop in prior consideration of the movement by inertia.
However, in recent years, the processing speeds of system apparatuses incorporating stapler apparatuses have become faster and varied, so to handle specifications for those processing speeds, the rotation count of the direct drive motor, which is the drive source for the stapler apparatuses themselves, is increased to increase the binding speeds thereby making it possible to handle the processing speeds of system apparatus to which they are incorporated.
However, although it is possible to increase binding speeds by increasing the number of rotations of the direct current motor, inertia also increases, thus it takes a longer amount of time for the direct current motor to stop from beginning the stopping operation until rotation is completely stopped under inertia. Nevertheless, it is structurally impossible to increase the idle position region for the increased stopping time in view of the space of the stapler apparatus itself. The result is that in using such idle position sensors like those of the prior art to grasp the position that the binding means has reached in the idle position region to begin stopping the direct current motor, the binding means will not stop within the idle position region and will over run it because of the inertia before stopping. This causes the problem of a narrowing of the opening of the nipping means that nips the binding media for the amount that was overrun thereby making it impossible to set the binding media.